Method of inhibiting degeneration of direct reduced iron

Abstract

A method of inhibiting degeneration of direct reduced iron by immersing the iron ore, after it has been reduced, in molten wax for a period of time sufficient for the wax to cover completely the surface of the iron and to enter the pores in the surface of the iron. The iron is preferably in the form of pellets which are conveyed in mesh baskets which are themselves immersed in the wax. The wax is preferably paraffin wax at a temperature of between 110° and 120° C.

I claim: 
     
       1. A method of processing iron ore, the method comprising: directly reducing iron ore to form porous or spongy direct reduced iron (DRI) material;   immersing said DRI material in molten wax to impregnate said material while the material is still hot from the direct reduction process and prior to reoxidation or other deterioration thereof; and   removing the DRI material from the molten wax, allowing wax to drain from the exterior surface of the DRI material, and permitting the wax within the pores of the DRI material to cool and harden, whereby the DRI material is protected against oxidation or other deterioration under adverse conditions.   
     
     
       2. A method as claimed in claim 1, in which said wax is paraffin wax. 
     
     
       3. A method as claimed in claim 1, wherein the temperature of the molten wax is between 110° and 120° C. 
     
     
       4. A method as claimed in claim 1, wherein the iron ore is at a temperature of between 90° to 100° C. at the time of immersion. 
     
     
       5. A method as claimed in claim 1, wherein the iron ore is in the form of pellets. 
     
     
       6. A method as claimed in claim 5, wherein the pellets are retained in mesh baskets having a mesh smaller than the average diameter of the pellets, the baskets being conveyed on a conveyor and being immersed in the molten wax which is contained in a vessel. 
     
     
       7. A method as claimed in claim 1, wherein said period of time is between 3 to 5 seconds. 
     
     
       8. A method of processing iron ore comprising the steps of: directly reducing pellets of iron ore to form metallic iron in the form of porous or sponge-like pellets;   removing the pellets from the direct reduction process while the pellets are still at a substantial elevated temperature above room temperature;   placing the pellets of directly reduced iron in mesh baskets having mesh openings smaller than the size of the pellets.   immersing the DRI pellets in the mesh baskets into tanks of molten wax to coat and impregnate the porous pellets, the foregoing step being accomplished while the pellets are still hot from the direction reduction process, before the pellets have cooled down, and prior to re-oxidation or other degeneration of the DRI pellets;   removing the coated DRI pellets from the molten wax and permitting the wax to cool and harden thereby coating the DRI pellets and permeating the pores thereof;   subsequently shipping the wax coated pellets to the point of final use of the pellets;   whereby deterioration of the DRI pellets during shipment is inhibited or substantially prevented.   
     
     
       9. A method as claimed in claim 8 in which said wax is paraffin wax. 
     
     
       10. A method as claimed in claim 8 wherein the temperature of the molten wax is between 110° and 120° C. 
     
     
       11. A method as claimed in claim 8 wherein the iron ore is at a temperature of between 90° to 100° C. at the time of immersion. 
     
     
       12. A method as defined in claim 8 wherein said DRI pellets are immersed in said molten wax for approximately 3 to 5 seconds. 
     
     
       13. A method of processing iron ore comprising the steps of: directly reducing iron ore to form porous or spongy DRI material pellets;   immersing said DRI material in molten wax to impregnate said material while the pellets are still hot from the direct reduction process, before the pellets have cooled down, and prior to re-oxidation or other deterioration thereof;   removing the DRI material from the molten wax and permitting the wax to cool and harden, thereby coating the DRI material and permeating the pores thereof; and   protecting the DRI material against oxidation or other deterioration under possible adverse conditions by maintaining the DRI material coated and impregnated with wax.   
     
     
       14. A process as defined in claim 13 wherein the immersing step is accomplished using wire mesh baskets permitting free flow of wax through the baskets to the DRI material.